The embedding of drain tubes, cables, or pipes and the like in the ground normally comprises the use of a penetrating body such as a plough having a plough blade or another member for the cutting of or penetration into a ground material so as to form a furrow or void for receiving the drain tubes, cables or pipes.
The drain tubes, cables or pipes which are to be laid down and ploughed under are typically continuously embedded into the furrow or void from a reel via a guide member which is normally mounted on the rear end of a tractor or other driving force pulling a plough.
Irrespective of whether the ground material is soft or hard, it is important that the penetrating bodies, such as cable ploughs, are able to form a furrow or void in which it is possible to lay the drain tubes, cables or pipes, as well as being able to function in many types of terrains or ground surfaces and at various depths.
Ploughs designed for embedding cables into the ground material are known from e.g. U.S. Pat. No. 4,892,443 and DE-B-1 484 388.
U.S. Pat. No. 4,892,443 describes a cable plough with a design which enables automatically setting suitable laying depths for different terrains or ground surfaces which may alternately include extremely soft and extremely hard formations so that the driving force of the plough simultaneously varies automatically in accordance with the ground conditions. The laying depth amounts to approximately 80 cm. It is stated that smaller penetration depths are adequate.
In order to obtain a more efficient embedding, ploughs including means for jetting a liquid are known from e.g. U.S. Pat. No. 3,638,439, U.S. Pat. No. 4,114,390, U.S. Pat. No. 4,812,079, U.S. Pat. No. 3,505,826, DE 29 37 406 C1 and DE 29 53 900 C2. The means for jetting of water are stated to be employed in order to obtain a more efficient embedding since the jetting of water is stated to be able to liquefy the ground material to be penetrated and thus facilitating the embedding.
U.S. Pat. No. 3,638,439, U.S. Pat. No. 4,114,390 and U.S. Pat. No. 4,812,079 describe an apparatus for the embedding of cablelike members under water.
U.S. Pat. No. 3,638,439 discloses an apparatus for embedding a cable-like member under water, comprising a water bed contacting support assembly, an entrance guide having a longitudinal axis, a depressor extending generally along a continuation of said axis rearward of said entrance guide, a jet assembly extending beneath said depressor and, connected to said jet assembly, a source of fluid under pressure for creating a jet flow to temporarily liquefy water bed soil in the path of said member without substantial permanent soil displacement, said flow rate being at least 300 gallons/minute and said pressure being no more than 300 p.s.i. The fluid utilized is water.
U.S. Pat. No. 4,114,390 discloses an apparatus for burying a conduit in the earth at the bottom of a body of water, comprising a frame adapted to be displaced along the conduit, and two sets of fluidization nozzles, one along the bottom of the frame and connected to means for supplying fluid at low velocity and low pressure thereto, and another one along the front of the frame, movable relative to the frame in a direction other than the direction of displacement of the frame and connected to means for supplying fluid at high velocity and high pressure thereto, the fluid utilized according to the patent specification being water.
U.S. Pat. No. 4,812,079 discloses an embedding apparatus for optionally cutting through different densities of soil and rock in order to embed cable in a water bed. The apparatus comprises a low pressure jet assembly for cutting into soil, a rock cutting assembly with teeth for cutting into soft rock, a rock-embedment depressor with a rotary saw blade assembly for cutting into relatively harder rock, and a depth sensor device. The fluid utilized is again, as in the case of the two above-mentioned documents, water.
U.S. Pat. No. 3,505,826 describes a method and an apparatus for the embedding of a pipeline into the ground of a water bed. The apparatus, a train of towed flushing and sucking elements, comprises means for spraying water jets into ground to be broken up hydraulically below the pipeline and suction tubes to remove the ground sludge from below the pipeline to places beside the pipeline route.
DE 29 37 406 C1 and DE 29 53 900 C2 both describe a mole plough for laying cables or pipes in marshy or water logged ground. The plough has a leading rotary saw or straight blade which is provided with jet pipes vertically mounted behind the cutting edge.